Punctuation can either clarify the written message or confuse its meaning. It pays to know how to use these small but powerful marks. Resist the temptation to punctuate according to guesswork. While careful use of punctuation enhances the meaning of what you write, idiosyncratic punctuation has the opposite effect.


See Diacritical Marks.


Commonly known as the and sign, the ampersand shouldn't be used as a replacement for and in reference to UO offices or policies. The ampersand may be used in the name of a nonuniversity business, such as an architecture, accounting, advertising, or law firm, if that is the standard procedure for that business.

arts and sciences
School of Journalism and Communication
Department of Computer and Information Science
the law offices of Morgan, Lewis & Bockius
Wieden & Kennedy


Of all punctuation marks, the apostrophe is the most abused. The most common misuses are inserting an apostrophe before the final s in a plural noun—where it doesn't belong—and omitting it from a possessive noun, where it does.

Prizes are awarded. (not Prize's are awarded.)
Have you seen the book's cover? (not Have you seen the books cover?)

Plural Nouns

Don't use apostrophes in plural nouns. This includes dates such as 1870s and 1990s. The only time you need to use an apostrophe in forming a plural is to avoid ambiguity. For instance, if you're writing about letter grades, you may need the apostrophe to distinguish A's from the word As.

ifs, ands, or buts
dos and don'ts
Make sure you dot your I's and cross your T's.

Possessive Nouns

Things as well as people can be possessive.

a master's degree
a month's pay
today's New York Times

Plural Possessive Nouns

In most cases, the possessive of plural nouns is formed by adding an apostrophe only (except for a few irregular plurals that do not end in s).

the puppies' paws
the Williamses' new house
children's literature

Possessive Pronouns

His, its, hers, theirs, yours, ours, and whose are possessive pronouns; they don't contain apostrophes. It's is not a possessive pronoun; it's a contraction of it is.

The book's end is better than its beginning.
It's kind of you to ask.

Names Ending in S

The possessive is formed with an additional s.

Dylan Thomas's poetry
the Ganges's source


The colon is often used to introduce a list or series. However, it's redundant to use a colon directly after such verbs as are and include.

Three types of examinations are offered: oral, take‑home, and in-class.
The course offerings include Spanish, marine biology, and medieval history.


Use commas to separate all the items in a series of three or more ending in and or or.

The university awards bachelor's, master's, and doctoral degrees.
The Department of German and Scandinavian offers courses in Danish, Finnish, Norwegian, and Swedish as well as in German.

The following example may appear to be an exception, but it isn't because there are only two items in the series: (1) planning, (2) public policy and (public) management.

Department of Planning, Public Policy and Management

Dashes—Em and En

Dashes aren't hyphens. The em dash (—) is longer than a hyphen and indicates a break in the syntax of a sentence.

Of the three grading options—graded only, pass/no pass only, either graded or pass/no pass—the last option is the default.

The en dash (–) is half as long as an em dash. Use an en dash to indicate continuing or inclusive numbers in dates, times, or reference numbers.

50 BC–AD 45
10:00 a.m.–5:00 p.m.
pp. 12–28

The en dash sometimes replaces a hyphen for clarification.

post–Civil War
a hospital–nursing home connection

Use an em dash when attributing a quote.

"You can never be overdressed or overeducated." —Oscar Wilde

Diacritical Marks

Words in other languages, and even a few adopted into English, sometimes have special marks above or beneath certain letters that provide help in pronunciation or meaning. Following are six of the most common diacritical marks used in Romance and Germanic languages when they are written in the same Latin alphabet we use in English. All except the cedilla can be used with letters besides the ones in the examples. When in doubt, use English.

Name Mark Example Meaning
acute accent é Renée a name (French)
grave accent è après 'after'
dieresis or umlaut ü München 'Munich' (German)
circumflex ê fête 'festival' (French)
tilde ñ año 'year' (Spanish)
cedilla ç reçu 'received' (French)

Download a list of key commands for diacritical marks.

An error occurred while trying to preview the media. Please save your work and reload this page.


Ditto Marks

Don't use them. Spell out.


Use ellipses (using three spaced periods, not a single-glyph three-dot ellipsis character) sparingly and only as specified below—not as a substitution for "etc." or as a design cliché. In the following examples, ellipses replace words in the original sentences without distorting their meaning.

original sentence:
The newspaper reporter, known worldwide for her frontline reporting, has received many awards for her war correspondence.

with ellipsis:
The newspaper reporter . . . has received many awards for her war correspondence.

original sentences:
The photojournalist barely escaped a falling timber as he stood under a tree, trying to show the forest fire from a fighter's perspective. His injuries left him shaken, though he was elated to capture the dangers of firefighting on film.

with ellipsis:
The photojournalist barely escaped a falling timber . . . though he was elated to capture the dangers of firefighting on film.

In quoted speech or conversation, faltering speech may be indicated by an ellipsis.

Exclamation Point

Overuse of the exclamation point imparts an adolescent quality to most writing. Use it sparingly to express surprise, disbelief, or other strong emotion. To quote F. Scott Fitzgerald, "An exclamation mark is like laughing at your own joke." For additional guidance, consult this handy chart from Hubspot.


Compound adjectives should be hyphenated to eliminate ambiguity of meaning. Otherwise, leave open.

first class mail
$2 million grant
study-abroad programs
fast-sailing ship
work-study student

Adverbs ending in -ly followed by an adjective aren't hyphenated.

a highly complex issue

Use a hyphen to distinguish confusing pairs of words.

recreation (but re-creation)
refund (but re-fund)

Use a hyphen after full or well when it's used in a compound modifier immediately before a noun, unless the word itself is modified.

a full-page advertisement
a well-known professor
a very well known professor

Don't use a hyphen when the modifier is in other positions in the sentence.

She works full time.
Although well known, the landmark is rarely visited.

The prefixes anti, co, post, pre, non, multi, and re generally don't require a hyphen unless followed by a proper noun. See also Dashes—Em and En.


Use a hyphen when using pro- to coin a word indicating support (e.g., pro-feminist).

After requires a hyphen when used to form a compound adjective but not when it's part of a compound noun.

after-dinner speech
afterglow and afternoon

Hyphenate an age when used as an adjective, even if the noun the adjective modifies is only implied rather than stated.

the five-year-old program
The five-year-old [child] attended kindergarten.

Hyphenate adjectives used to define measures.

the seven-foot-one center of the Los Angeles Lakers

Hyphenate the noun co-op when abbreviating cooperative, but don't hyphenate cooperate, coordinate, or coeducational.

Don't use a hyphen in a compound noun with vice:

vice chancellor
vice president
vice provost

Hyphenate the construction student-athlete.

For further examples, refer to The Chicago Manual of Style's hyphenation guide.


Italics are used for titles of books, genera and species, long plays, periodicals, movies, newspapers, operas and other long musical compositions, ships, and works of art. Titles of television and radio series are italicized, but titles of individual episodes are placed in quotation marks.

Woolf's To the Lighthouse
Bizet's Carmen
O'Keeffe's Cow's Skull, Red, White, and Blue
Shaw's Major Barbara
Wertmuller's Seven Beauties
National Public Radio's All Things Considered
"Eye of the Beholder," Rod Serling's classic episode of The Twilight Zone, is regarded by many fans as a high point for the series.

Some musical compositions are known by their generic titles—symphony, quartet, nocturne—and often a number or key or both. Such names are capitalized but not italicized. For example, Beethoven's Piano Sonata No. 14 in C-sharp minor, Op. 25, would not be italicized; however, its nongeneric subtitle, Moonlight Sonata, would.

The titles of university courses follow the standard rules for capitalization of the titles of works; they are neither italicized nor placed in quotation marks.

Introduction to Biological Anthropology (ANTH 270) has no prerequisite.

Italics are also used for unfamiliar foreign words. Words that were originally borrowed from another language but have been permanently added to the English lexicon (i.e., if they're in an English dictionary) should not be italicized.

samizdat ‘underground'
asperge ‘asparagus'
hors d'oeuvres (no ligature between o and e)

Use specific, concrete language rather than italics, capitals, or quotation marks for emphasis.

This committee consists of two, not three, people.
This committee is composed of two (2) people.


Use parentheses for enumeration within the text as follows:

(1) carbohydrates, (2) fat, (3) protein, (4) vitamins

For enumeration with periods, see also Numbers.

Parentheses sometimes enclose brief explanatory abbreviations.

McKenzie Hall (formerly the Law Center) houses offices for the College of Arts and Sciences.
The writing requirement for a bachelor's degree is College Composition I (WR 121) and either College Composition II or III (WR 122 or 123).

Punctuation in Lists

When the items in a list are sentence fragments, no ending punctuation is necessary. When the items form complete sentences, a punctuation mark, usually a period or semicolon, may be used at their terminus.

receipt date
Placement is dependent on the date the application is received.

The style chosen for the list should be consistent. Do not mix and match sentence fragments and complete sentences within a list.

Quotation Marks

Use double quotation marks before and after direct quotations as well as titles of interviews, personal correspondence, short poems and plays, short musical compositions, speeches, individual television or radio programs, and other unpublished writing.

The poem is titled "If."
"Freedom of the Free Press" was the title of her lecture.

Use single quotation marks for quotations within quotations.

I said, "You must know who shouted, ‘Eureka! I've found it!'"

Put a period or comma inside the ending quotation mark.

Professor Ogard's newly published article is "China in Transition."
Caldwell's lecture, "Death and Life in American Law," is at 7:30 p.m. in 129 McKenzie Hall.

Put an exclamation point, question mark, or semicolon inside the ending quotation mark only if it's part of the quotation.

"Who's on First?" is one of Abbott and Costello's classic comedy routines.

Put an exclamation point, question mark, or semicolon outside the ending quotation mark if it isn't part of the quotation.

Are you going to read "China in Transition"?

Don't use quotation marks after the word so-called. It's redundant.

The so-called transient (not "transient") was a college student.

Use quotation marks around unusual, technical, ironic, or slang words or phrases not accompanied by a word calling attention to them. Use this device sparingly, and on first use only.

The "transient" was a college student.
Thousands of dollars were raised in support of the Interior Architecture Program's "daylighting" research.

Solidus (Slash)

The solidus (also known as the slash or virgule) is overused and frequently ambiguous. Too often, the relationship between the items joined by a solidus is unclear. Does it mean and, either ... or, or does it simply link two closely related words?

As defined by The American Heritage Dictionary of the English Language, the solidus is used to separate alternatives, such as and/or. It is appropriate, then, to use the solidus in pass/no pass or in P/N. In most other cases, try to use words instead of the solidus.

faculty or staff member (not faculty/staff)

Use a hyphen instead of a solidus to link two words.

middle-secondary education (not middle/secondary)

If space limitations make it necessary to use a solidus, explain clearly what it means.

Courses numbered 4XX/5XX are for seniors and graduate students, respectively. Although undergraduates and graduates share the same classroom, graduate students are required to do more work, are evaluated according to a tougher grading standard, or both.

Use the solidus with a space on either side to separate two lines of poetry quoted in the text.

In "Song of the Open Road," Ogden Nash wrote, "I think that I shall never see / A billboard lovely as a tree."